The present invention relates to a process cartridge detachably mountable to an electrophotographic image forming apparatus and a process cartridge mounting and demounting mechanism.
Here, the electrophotographic image forming apparatus forms an image on a recording material through an electrophotographic image formation type process. Examples of the electrophotographic image forming apparatus include an electrophotographic copying machine, an electrophotographic printer (laser beam printer, LED printer or the like), the facsimile machine, a word processor or a complex machine (multifunction printer or the like) or the like.
The process cartridge integrally contains an electrophotographic photosensitive drum, and charging means, developing means or cartridge, in the form of a unit or a cartridge, which is detachably mountable to a main assembly of an image forming apparatus. The process cartridge may contain the electrophotographic photosensitive drum, and at least one of charging means, developing means and cleaning means, in the form of a cartridge which is detachably mountable to the main assembly of the image forming apparatus. Or, it may be a cartridge containing integrally at least developing means and an electrophotographic photosensitive member, the cartridge being the detachably mountable to a main assembly of an image forming apparatus.
In an electrophotographic image forming apparatus using the electrophotographic image forming process, use has been made with the process cartridge type in which the process cartridge comprises as a unit the electrophotographic photosensitive member and process means actable on the electrophotographic photosensitive member, the unit being detachably mountable to the main assembly of the electrophotographic image forming apparatus. With the use of the process cartridge type, the maintenance operation can be carried out in effect by the users without necessity of relying on serviceman, and therefore, the operativity is improved. Therefore, the process cartridge type machines are widely used in the field of the image forming apparatus.
In order to provide satisfactory images by the electrophotographic image forming apparatus using such a process cartridge, it is necessary that process cartridge is mounted at a predetermined position in the main assembly of the electrophotographic image forming apparatus to establish correct connection of the interface portions such as various electrical contacts and a drive transmitting portion.
Referring first to FIG. 60 and FIG. 61, there are shown a process cartridge PC (FIG. 60) and a guide groove GL provided in the main assembly PR of the image forming apparatus (FIG. 61). FIG. 62 shows an image forming apparatus employing of such a process cartridge PC.
As shown in FIGS. 60-62, in the mounting-and-demounting of the process cartridge PC relative to the main assembly PR of the image forming apparatus, a positioning boss CB is provided on the axis of an electrophotographic photosensitive member in the form of a photosensitive drum provided in the process cartridge PC, and on the other hand, the main assembly PR of the image forming apparatus is provided with a guide groove GL for guiding and positioning the positioning boss CB of the process cartridge. When the user inserts the process cartridge PC along the mounting guide CL (cartridge mounting guide) to a predetermined position, an abutting portion P provided on the main assembly PR of the image forming apparatus is abutted to the process cartridge PC to prevent rotation about the positioning boss CB. The apparatus of such a structure has been put into practice.
As shown in FIG. 62, the process cartridge PC is provided with a drum shutter DS which functions to cover the surface of the photosensitive drum when the process cartridge PC is out of the main assembly PR of the image forming apparatus and to expose the surface of the photosensitive drum when the process cartridge PC is mounted in the main assembly PR of the image forming apparatus. The opening and closing of the drum shutter DS is carried out in interrelation with inserting operation of the process cartridge PC into the main assembly PR of the image forming apparatus or with the removal thereof.
An urging means for urging the process cartridge PC in the mounting direction has been proposed and put into practice, wherein the charging means is provided on the opening and closing cover C of the main assembly PR of the image forming apparatus.
As shown in FIG. 62, another proposal has been made in which a back cover UC having a shape corresponding to the outer configuration of the process cartridge PC is fixed to the inside of the cover C, and the process cartridge PC is urged to a regular position by closing the cover C.
The present invention provides a further development of the prior-art technique.
Accordingly, it is a principal object of the present invention to provide a process cartridge and a process cartridge mounting and demounting mechanism with which the mounting operationality!kP when the process cartridge is mounted to the main assembly of the apparatus is improved.
It is another object of the present invention to provide a process cartridge and a mounting and demounting mechanism for the process cartridge with which the process cartridge can be automatically mounted to a mounting position in the main assembly of apparatus.
It is a further object of the present invention to provide a process cartridge and a mounting and demounting mechanism for the process cartridge with which the process cartridge can be mounted to the mounting positions of the main assembly of apparatus in interrelation with a closing operation of an openable member.
It is a further object of the present invention to provide a process cartridge and a mounting and demounting mechanism for the process cartridge with which the process cartridge can be automatically mounted to or demounted from a mounting position of the main assembly opened apparatus.
It is a further object of the present invention to provide a process cartridge and a mounting and demounting mechanism for the process cartridge in which the mounting and demounting mounting and demounting operationality.
It is a further object of the present invention to provide a process cartridge and a mounting and demounting mechanism for the process cartridge in which the process cartridge can be conveyed to a mounting position of an image forming apparatus with a closing action of the opening and closing member.
It is a further object of the present invention to provide a process cartridge and a mounting and demounting mechanism for the process cartridge in which the process cartridge is moved toward a mounting position along such a direction that transfer roller is pushed in, in accordance with a closing operation of an opening and closing member, by which the positional deviation of the electrophotographic photosensitive member is minimized in the direction in which a recording material is fed.
It is a further object of the present invention to provide a mounting and demounting mechanism for the process cartridge and a process cartridge in which a user inserts the process cartridge downwardly in a slanted direction into the electrophotographic image forming apparatus having a transfer roller for transferring an image onto a recording material by being urged to the photosensitive drum, and then, the photosensitive drum of the process cartridge is conveyed substantially in a horizontal direction in interrelation with an opening and closing operation of an opening and closing member; when the photosensitive drum reaches neighborhood of the transfer roller, the process cartridge is mounted such that photosensitive drum is moved downwardly in a slanted direction, thus facilitating insertion of the transfer roller.
It is a further object of the present invention to provide a mounting and demounting mechanism for a process cartridge and a process cartridge in which the process cartridge can be mounted or the mounted in interrelation with opening and closing operation of the opening and closing member, and when the process cartridge moves in interrelation with the opening and closing operation of the opening and closing cover, the drum shutter can be opened or closed.
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.